Studies of somatostatin, cortisol, and beta-endorphin in relation to affective and other neuropsychiatric disorders have continued. Findings consist of the following. 1) Somatostatin - Evidence of a nocturnal increase in CSF somatostatin in normal controls during a 30-hour CSF study; 2) Preliminary evidence of decreased somatostatin following ECT in the 30-hour CSF study; 3) Increased CSF somatostatin following treatment with nimodipine. As a preliminary to the investigation of gonadal steroids and stress on serotonin receptor ontogeny, we have demonstrated the pattern of embryonic and post-natal expression of eight serotonin receptor subtypes in the hippocampus of rat brain. Patterns vary from declining post-natal expression (5-HT1A and 5-HT1B) to increasing post-natal expression (5-HT1C, 5-HT1D, 5-HT1F, 5-HT3).